Background and aims: Hepatic lipase (HL) catalyzes the hydrolysis of triglycerides and phospholipids from lipoproteins, and promotes the hepatic uptake of lipoproteins. A common G-250A polymorphism in the promoter of the hepatic lipase gene (LIPC) has been described. The aim was to study the effects of the G-250A polymorphism on HL activity, serum lipid profile and insulin sensitivity.
Methods and results: Altogether 151 healthy subjects (age 49+/-8 years, BMI 26.5+/-3.0kg/m(2)) were randomly assigned for 3 months to an isoenergetic diet containing either a high proportion of saturated fatty acids (SFA diet) or monounsaturated fatty acids (MUFA diet). Within groups there was a second random assignment to supplements with fish oil (3.6g n-3 FA/day) or placebo. At baseline, the A-250A genotype was associated with high serum LDL cholesterol concentration (P=0.030 among three genotypes). On the MUFA diet carriers of the A-250A genotype presented a greater decrease in LDL cholesterol concentration than subjects with other genotypes (P=0.007 among three genotypes). The rare -250A allele was related to low HL activity (P<0.001 among three genotypes). The diet did not affect the levels of HL activity among the genotypes.
Conclusion: The A-250A genotype of the LIPC gene was associated with high LDL cholesterol concentration, but the MUFA-enriched diet reduced serum LDL cholesterol concentration especially in subjects with the A-250A genotype.